Group indicator for code block group based retransmission in wireless communication

ABSTRACT

Aspects of the present disclosure provide a code block group (CBG) based HARQ retransmission process in which HARQ retransmission is performed based on CBG units. The CBG based HARQ process uses a CBG failure mask that can reduce the signaling overhead of CBG-based HARQ retransmissions. A base station can determine the error CBGs from different UEs that share a slot, and generate a CBG failure mask that capture all the CBGs NACKs from the UEs.

PRIORITY CLAIM

This application claims priority to and the benefit of U.S. provisionalpatent application No. 62/471,863 filed in the United States Patent andTrademark Office on Mar. 15, 2017, the entire content of which isincorporated herein by reference as if fully set forth below in itsentirety and for all applicable purposes.

TECHNICAL FIELD

The technology discussed below relates generally to wirelesscommunication systems, and more particularly, to code block group (CBG)based hybrid automatic repeat request (HARQ) signaling in wirelesscommunication.

INTRODUCTION

In some wireless communication networks, a physical layer receivespayload data from an upper layer (e.g., MAC layer) as one or moretransport blocks that correspond to a MAC protocol data unit. The sizeof a transport block (TB) may be chosen based on various parameters.Different TB sizes may be used for different scenarios. For example,some of the parameters are an amount of data available for transmission,modulation and coding scheme (MCS), and resources (e.g., time andfrequency resources) available for transmitting the data. One TB may betransmitted as multiple time domain symbols in a slot. When one or moresymbols is not successfully transmitted to a receiving device, thecorresponding TB may be retransmitted using a hybrid automatic repeatrequest (HARQ) process or the like.

BRIEF SUMMARY OF SOME EXAMPLES

The following presents a simplified summary of one or more aspects ofthe present disclosure, in order to provide a basic understanding ofsuch aspects. This summary is not an extensive overview of allcontemplated features of the disclosure, and is intended neither toidentify key or critical elements of all aspects of the disclosure norto delineate the scope of any or all aspects of the disclosure. Its solepurpose is to present some concepts of one or more aspects of thedisclosure in a simplified form as a prelude to the more detaileddescription that is presented later.

Aspects of the present disclosure provide a code block group (CBG) basedhybrid automatic repeat request (HARQ) retransmission process in whichHARQ retransmission is performed based on CBG units. The CBG based HARQprocess uses a CBG failure mask that can reduce the signaling overheadof CBG-based HARQ retransmissions. A base station can determine theerror CBGs from different UEs that share a slot, and generate a CBGfailure mask that capture all the CBGs NACKs from the UEs.

One aspect of the present disclosure provides a method of wirelesscommunication operable at a scheduling entity. The scheduling entityreceives a first uplink (UL) transmission that includes a plurality offirst code block groups (CBGs) from a first user equipment (UE) and asecond UL transmission that includes a plurality of second CBGs from asecond UE. The scheduling entity determines decoding error in one ormore CBGs among the first and second CBGs. The scheduling entitygenerates a CBG failure mask indicating the decoding error, and the CBGfailure mask is configured to indicate one or more time-frequency domainregions covering the one or more CBGs with the decoding error. Thescheduling entity transmits the CBG failure mask to the first UE and thesecond UE to facilitate retransmission of the CBGs indicated by the CBGfailure mask. For example, the UE may retransmit the CBG(s) using a HARQprocess.

Another aspect of the present disclosure provides a method of wirelesscommunication operable at a first user equipment (UE). The UE transmitsan uplink (UL) transmission to a scheduling entity, and the ULtransmission carries a plurality of code block groups (CBGs). The UEreceives a CBG failure mask from the scheduling entity, and the CBGfailure mask covers a time-frequency domain region designated for CBGretransmission. The UE compares time-frequency resources of thetransmitted CBGs with time-frequency resources in the time-frequencydomain region of the CBG failure mask, to determine one or more of theCBGs for retransmission. Then, the UE transmits the one or more CBGs forretransmission.

Another aspect of the present disclosure provides a scheduling entity.The scheduling entity includes a communication interface configured tocommunicate with a first user equipment (UE) and a second UE, a memory,and a processor operatively coupled to the communication interface andthe memory. The processor and the memory are configured to receive afirst uplink (UL) transmission from the first UE and a second ULtransmission from the second UE. The first UL transmission includes aplurality of first code block groups (CBGs). The second UL transmissionincludes a plurality of second CBGs. The processor and the memory areconfigured to determine decoding error in one or more CBGs among thefirst and second CBGs. The processor and the memory are configured togenerate a CBG failure mask indicating the decoding error. The CBGfailure mask is configured to indicate one or more time-frequency domainregions covering the one or more CBGs with the decoding error. Theprocessor and the memory are configured to transmit the CBG failure maskto the first UE and the second UE to facilitate retransmission of theCBGs indicated by the CBG failure mask.

Another aspect of the present disclosure provides a first user equipment(UE). The first UE includes a communication interface configured tocommunicate with a scheduling entity, a memory, and a processoroperatively coupled to the communication interface and the memory. Theprocessor and the memory are configured to transmit an uplink (UL)transmission to the scheduling entity, and the UL transmission carries aplurality of code block groups (CBGs). The processor and the memory areconfigured to receive a CBG failure mask from the scheduling entity, andthe CBG failure mask includes a time-frequency domain region designatedfor CBG retransmission. The processor and the memory are configured tocompare time-frequency resources of the transmitted CBGs withtime-frequency resources in the time-frequency domain region of the CBGfailure mask, to determine one or more of the CBGs for retransmission.The processor and the memory are configured to transmit the one or moreCBGs for retransmission.

These and other aspects of the invention will become more fullyunderstood upon a review of the detailed description, which follows.Other aspects, features, and embodiments of the present invention willbecome apparent to those of ordinary skill in the art, upon reviewingthe following description of specific, exemplary embodiments of thepresent invention in conjunction with the accompanying figures. Whilefeatures of the present invention may be discussed relative to certainembodiments and figures below, all embodiments of the present inventioncan include one or more of the advantageous features discussed herein.In other words, while one or more embodiments may be discussed as havingcertain advantageous features, one or more of such features may also beused in accordance with the various embodiments of the inventiondiscussed herein. In similar fashion, while exemplary embodiments may bediscussed below as device, system, or method embodiments it should beunderstood that such exemplary embodiments can be implemented in variousdevices, systems, and methods.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a wireless communication system.

FIG. 2 is a conceptual illustration of an example of a radio accessnetwork.

FIG. 3 is a diagram illustrating an orthogonal frequency divisionmultiplexing (OFDM) waveform in wireless communication.

FIG. 4 is a block diagram conceptually illustrating an exemplarytransport block according to some aspects of the disclosure.

FIG. 5 is a diagram illustrating an uplink slot for wirelesscommunication according to some aspects of the disclosure.

FIG. 6 is a diagram illustrating a code block group (CBG) basedretransmission process utilizing a CBG failure mask according to someaspects of the disclosure.

FIG. 7 is a diagram illustrating an exemplary process for generating aCBG failure mask according to some aspects of the disclosure.

FIG. 8 is a diagram illustrating an exemplary process for determining aCBG for retransmission using a CBG failure mask according to someaspects of the disclosure.

FIG. 9 is a diagram illustrating an exemplary CBG failure mask for anuplink slot according to some aspects of the disclosure.

FIG. 10 is a diagram illustrating another exemplary CBG failure mask foran uplink slot according to some aspects of the disclosure.

FIG. 11 is a block diagram conceptually illustrating an example of ahardware implementation for a scheduling entity according to someaspects of the disclosure.

FIG. 12 is a flow chart illustrating an exemplary process for wirelesscommunication at a scheduling entity utilizing a CBG failure maskaccording to some aspects of the disclosure.

FIG. 13 is a block diagram conceptually illustrating an example of ahardware implementation for a scheduled entity according to some aspectsof the disclosure.

FIG. 14 is a flow chart illustrating an exemplary process for wirelesscommunication at a user equipment utilizing a CBG failure mask accordingto some aspects of the disclosure.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appendeddrawings is intended as a description of various configurations and isnot intended to represent the only configurations in which the conceptsdescribed herein may be practiced. The detailed description includesspecific details for the purpose of providing a thorough understandingof various concepts. However, it will be apparent to those skilled inthe art that these concepts may be practiced without these specificdetails. In some instances, well-known structures and components areshown in block diagram form in order to avoid obscuring such concepts.

While aspects and embodiments are described in this application byillustration to some examples, those skilled in the art will understandthat additional implementations and use cases may come about in manydifferent arrangements and scenarios. Innovations described herein maybe implemented across many different platform types, devices, systems,shapes, sizes, packaging arrangements. For example, embodiments and/oruses may come about via integrated chip embodiments and othernon-module-component based devices (e.g., end-user devices, vehicles,communication devices, computing devices, industrial equipment,retail/purchasing devices, medical devices, AI-enabled devices, etc.).While some examples may or may not be specifically directed to use casesor applications, a wide assortment of applicability of describedinnovations may occur. Implementations may range a spectrum fromchip-level or modular components to non-modular, non-chip-levelimplementations and further to aggregate, distributed, or OEM devices orsystems incorporating one or more aspects of the described innovations.In some practical settings, devices incorporating described aspects andfeatures may also necessarily include additional components and featuresfor implementation and practice of claimed and described embodiments.For example, transmission and reception of wireless signals necessarilyinclude a number of components for analog and digital purposes (e.g.,hardware components including antenna, RF-chains, power amplifiers,modulators, buffer, processor(s), interleaver, adders/summers, etc.). Itis intended that innovations described herein may be practiced in a widevariety of devices, chip-level components, systems, distributedarrangements, end-user devices, etc. of varying sizes, shapes andconstitution.

In a 5G NR network, interference may be more bursty. A transmittingdevice may transmit a transport block (TB) that includes multiple codeblocks (CBs) grouped into different code block groups. Burstyinterference may affect only some of the CBs. In some examples, burstyinterference may be caused by higher priority traffic such asultra-reliable and low-latency communication (URLLC) or the like. Toincrease efficiency, retransmission of a TB may be performed in codeblock group (CBG) unit. For a certain TB, CB Gs that are successfullytransmitted need not be retransmitted when retransmission is performedin CBG unit. In various examples, a CBG may include any number of CBs.In one example, a CBG may include one code block (CB). In anotherexample, a CBG may include any number of CBs or all CBs of a TB. Byretransmitting only CBG(s) that is/are affected by bursty interference,retransmission efficiency may be improved and/or overhead may bereduced. Performing retransmission in CBG unit can provide a balancebetween retransmission feedback overhead and retransmission efficiency.

Aspects of the present disclosure provide various CBG basedretransmission signaling schemes that can improve CBG-based dataretransmission efficiency. In some examples, when an interferencepattern (e.g., bursty interference) is similar across a relatively largeportion of communication bandwidth, a common or group indicator may beused to signal CBG based uplink retransmission such that downlinksignaling overhead may be reduced. The common or group indicator isconfigured to provide CBG retransmission information for multiple userequipments in order to reduce control signaling overhead.

The various concepts presented throughout this disclosure may beimplemented across a broad variety of telecommunication systems, networkarchitectures, and communication standards. Referring now to FIG. 1, asan illustrative example without limitation, various aspects of thepresent disclosure are illustrated with reference to a wirelesscommunication system 100. The wireless communication system 100 includesthree interacting domains: a core network 102, a radio access network(RAN) 104, and a user equipment (UE) 106. By virtue of the wirelesscommunication system 100, the UE 106 may be enabled to carry out datacommunication with an external data network 110, such as (but notlimited to) the Internet.

The RAN 104 may implement any suitable wireless communication technologyor technologies to provide radio access to the UE 106. As one example,the RAN 104 may operate according to 3^(rd) Generation PartnershipProject (3GPP) New Radio (NR) specifications, often referred to as 5G.As another example, the RAN 104 may operate under a hybrid of 5G NR andEvolved Universal Terrestrial Radio Access Network (eUTRAN) standards,often referred to as LTE. The 3GPP refers to this hybrid RAN as anext-generation RAN, or NG-RAN. Of course, many other examples may beutilized within the scope of the present disclosure.

As illustrated, the RAN 104 includes a plurality of base stations 108.Broadly, a base station is a network element in a radio access networkresponsible for radio transmission and reception in one or more cells toor from a UE. In different technologies, standards, or contexts, a basestation may variously be referred to by those skilled in the art as abase transceiver station (BTS), a radio base station, a radiotransceiver, a transceiver function, a basic service set (BSS), anextended service set (ESS), an access point (AP), a Node B (NB), aneNode B (eNB), a gNode B (gNB), or some other suitable terminology.

The radio access network 104 is further illustrated supporting wirelesscommunication for multiple mobile apparatuses. A mobile apparatus may bereferred to as user equipment (UE) in 3GPP standards, but may also bereferred to by those skilled in the art as a mobile station (MS), asubscriber station, a mobile unit, a subscriber unit, a wireless unit, aremote unit, a mobile device, a wireless device, a wirelesscommunications device, a remote device, a mobile subscriber station, anaccess terminal (AT), a mobile terminal, a wireless terminal, a remoteterminal, a handset, a terminal, a user agent, a mobile client, aclient, or some other suitable terminology. A UE may be an apparatusthat provides a user with access to network services.

Within the present document, a “mobile” apparatus need not necessarilyhave a capability to move, and may be stationary. The term mobileapparatus or mobile device broadly refers to a diverse array of devicesand technologies. UEs may include a number of hardware structuralcomponents sized, shaped, and arranged to help in communication; suchcomponents can include antennas, antenna arrays, RF chains, amplifiers,one or more processors, etc. electrically coupled to each other. Forexample, some non-limiting examples of a mobile apparatus include amobile, a cellular (cell) phone, a smartphone, a session initiationprotocol (SIP) phone, a laptop, a personal computer (PC), a notebook, anetbook, a smartbook, a tablet, a personal digital assistant (PDA), anda broad array of embedded systems, e.g., corresponding to an “Internetof things” (IoT). A mobile apparatus may additionally be an automotiveor other transportation vehicle, a remote sensor or actuator, a robot orrobotics device, a satellite radio, a global positioning system (GPS)device, an object tracking device, a drone, a multi-copter, aquad-copter, a remote control device, a consumer and/or wearable device,such as eyewear, a wearable camera, a virtual reality device, a smartwatch, a health or fitness tracker, a digital audio player (e.g., MP3player), a camera, a game console, etc. A mobile apparatus mayadditionally be a digital home or smart home device such as a homeaudio, video, and/or multimedia device, an appliance, a vending machine,intelligent lighting, a home security system, a smart meter, etc. Amobile apparatus may additionally be a smart energy device, a securitydevice, a solar panel or solar array, a municipal infrastructure devicecontrolling electric power (e.g., a smart grid), lighting, water, etc.;an industrial automation and enterprise device; a logistics controller;agricultural equipment; military defense equipment, vehicles, aircraft,ships, and weaponry, etc. Still further, a mobile apparatus may providefor connected medicine or telemedicine support, e.g., health care at adistance. Telehealth devices may include telehealth monitoring devicesand telehealth administration devices, whose communication may be givenpreferential treatment or prioritized access over other types ofinformation, e.g., in terms of prioritized access for transport ofcritical service data, and/or relevant QoS for transport of criticalservice data.

Wireless communication between a RAN 104 and a UE 106 may be describedas utilizing an air interface. Transmissions over the air interface froma base station (e.g., base station 108) to one or more UEs (e.g., UE106) may be referred to as downlink (DL) transmission. In accordancewith certain aspects of the present disclosure, the term downlink mayrefer to a point-to-multipoint transmission originating at a schedulingentity (described further below; e.g., base station 108). Another way todescribe this scheme may be to use the term broadcast channelmultiplexing. Transmissions from a UE (e.g., UE 106) to a base station(e.g., base station 108) may be referred to as uplink (UL)transmissions. In accordance with further aspects of the presentdisclosure, the term uplink may refer to a point-to-point transmissionoriginating at a scheduled entity (described further below; e.g., UE106).

In some examples, access to the air interface may be scheduled, whereina scheduling entity (e.g., a base station 108) allocates resources forcommunication among some or all devices and equipment within its servicearea or cell. Within the present disclosure, as discussed further below,the scheduling entity may be responsible for scheduling, assigning,reconfiguring, and releasing resources for one or more scheduledentities. That is, for scheduled communication, UEs 106, which may bescheduled entities, may utilize resources allocated by the schedulingentity 108.

Base stations 108 are not the only entities that may function asscheduling entities. That is, in some examples, a UE may function as ascheduling entity, scheduling resources for one or more scheduledentities (e.g., one or more other UEs).

As illustrated in FIG. 1, a scheduling entity 108 may broadcast downlinktraffic 112 to one or more scheduled entities 106. Broadly, thescheduling entity 108 is a node or device responsible for schedulingtraffic in a wireless communication network, including the downlinktraffic 112 and, in some examples, uplink traffic 116 from one or morescheduled entities 106 to the scheduling entity 108. On the other hand,the scheduled entity 106 is a node or device that receives downlinkcontrol information 114, including but not limited to schedulinginformation (e.g., a grant), synchronization or timing information, orother control information from another entity in the wirelesscommunication network such as the scheduling entity 108.

In general, base stations 108 may include a backhaul interface forcommunication with a backhaul portion 120 of the wireless communicationsystem. The backhaul 120 may provide a link between a base station 108and the core network 102. Further, in some examples, a backhaul networkmay provide interconnection between the respective base stations 108.Various types of backhaul interfaces may be employed, such as a directphysical connection, a virtual network, or the like using any suitabletransport network.

The core network 102 may be a part of the wireless communication system100, and may be independent of the radio access technology used in theRAN 104. In some examples, the core network 102 may be configuredaccording to 5G standards (e.g., 5GC). In other examples, the corenetwork 102 may be configured according to a 4G evolved packet core(EPC), or any other suitable standard or configuration.

FIG. 2 is a conceptual illustration of an example of a radio accessnetwork (RAN) 200. The RAN 200 may be the same as the RAN 104 describedabove and illustrated in FIG. 1. The geographic area covered by the RAN200 may be divided into cellular regions (cells) that can be uniquelyidentified by a user equipment (UE) based on an identificationbroadcasted from one access point or base station. FIG. 2 illustratesmacrocells 202, 204, and 206, and a small cell 208, each of which mayinclude one or more sectors (not shown). A sector is a sub-area of acell. All sectors within one cell are served by the same base station. Aradio link within a sector can be identified by a single logicalidentification belonging to that sector. In a cell that is divided intosectors, the multiple sectors within a cell can be formed by groups ofantennas with each antenna responsible for communication with UEs in aportion of the cell.

In FIG. 2, two base stations 210 and 212 are shown in cells 202 and 204;and a third base station 214 is shown controlling a remote radio head(RRH) 216 in cell 206. That is, a base station can have an integratedantenna or can be connected to an antenna or RRH by feeder cables. Inthe illustrated example, the cells 202, 204, and 126 may be referred toas macrocells, as the base stations 210, 212, and 214 support cellshaving a large size. Further, a base station 218 is shown in the smallcell 208 (e.g., a microcell, picocell, femtocell, home base station,home Node B, home eNode B, etc.) which may overlap with one or moremacrocells. In this example, the cell 208 may be referred to as a smallcell, as the base station 218 supports a cell having a relatively smallsize. Cell sizing can be done according to system design as well ascomponent constraints.

It is to be understood that the radio access network 200 may include anynumber of wireless base stations and cells. Further, a relay node may bedeployed to extend the size or coverage area of a given cell. The basestations 210, 212, 214, 218 provide wireless access points to a corenetwork for any number of mobile apparatuses. In some examples, the basestations 210, 212, 214, and/or 218 may be the same as the basestation/scheduling entity 108 described above and illustrated in FIG. 1.

FIG. 2 further includes a quadcopter or drone 220, which may beconfigured to function as a base station. That is, in some examples, acell may not necessarily be stationary, and the geographic area of thecell may move according to the location of a mobile base station such asthe quadcopter 220.

Within the RAN 200, the cells may include UEs that may be incommunication with one or more sectors of each cell. Further, each basestation 210, 212, 214, 218, and 220 may be configured to provide anaccess point to a core network 102 (see FIG. 1) for all the UEs in therespective cells. For example, UEs 222 and 224 may be in communicationwith base station 210; UEs 226 and 228 may be in communication with basestation 212; UEs 230 and 232 may be in communication with base station214 by way of RRH 216; UE 234 may be in communication with base station218; and UE 236 may be in communication with mobile base station 220. Insome examples, the UEs 222, 224, 226, 228, 230, 232, 234, 236, 238, 240,and/or 242 may be the same as the UE/scheduled entity 106 describedabove and illustrated in FIG. 1.

In some examples, a mobile network node (e.g., quadcopter 220) may beconfigured to function as a UE. For example, the quadcopter 220 mayoperate within cell 202 by communicating with base station 210.

In a further aspect of the RAN 200, sidelink signals may be used betweenUEs without necessarily relying on scheduling or control informationfrom a base station. For example, two or more UEs (e.g., UEs 226 and228) may communicate with each other using peer to peer (P2P) orsidelink signals 227 without relaying that communication through a basestation (e.g., base station 212). In a further example, UE 238 isillustrated communicating with UEs 240 and 242. Here, the UE 238 mayfunction as a scheduling entity or a primary sidelink device, and UEs240 and 242 may function as a scheduled entity or a non-primary (e.g.,secondary) sidelink device. In still another example, a UE may functionas a scheduling entity in a device-to-device (D2D), peer-to-peer (P2P),or vehicle-to-vehicle (V2V) network, and/or in a mesh network. In a meshnetwork example, UEs 240 and 242 may optionally communicate directlywith one another in addition to communicating with the scheduling entity238. Thus, in a wireless communication system with scheduled access totime-frequency resources and having a cellular configuration, a P2Pconfiguration, or a mesh configuration, a scheduling entity and one ormore scheduled entities may communicate utilizing the scheduledresources.

In the radio access network 200, the ability for a UE to communicatewhile moving, independent of its location, is referred to as mobility.The various physical channels between the UE and the radio accessnetwork are generally set up, maintained, and released under the controlof an access and mobility management function (AMF, not illustrated,part of the core network 102 in FIG. 1), which may include a securitycontext management function (SCMF) that manages the security context forboth the control plane and the user plane functionality, and a securityanchor function (SEAF) that performs authentication.

In various aspects of the disclosure, a radio access network 200 mayutilize DL-based mobility or UL-based mobility to enable mobility andhandovers (i.e., the transfer of a UE's connection from one radiochannel to another). In a network configured for DL-based mobility,during a call with a scheduling entity, or at any other time, a UE maymonitor various parameters of the signal from its serving cell as wellas various parameters of neighboring cells. Depending on the quality ofthese parameters, the UE may maintain communication with one or more ofthe neighboring cells. During this time, if the UE moves from one cellto another, or if signal quality from a neighboring cell exceeds thatfrom the serving cell for a given amount of time, the UE may undertake ahandoff or handover from the serving cell to the neighboring (target)cell. For example, UE 224 (illustrated as a vehicle, although anysuitable form of UE may be used) may move from the geographic areacorresponding to its serving cell 202 to the geographic areacorresponding to a neighbor cell 206. When the signal strength orquality from the neighbor cell 206 exceeds that of its serving cell 202for a given amount of time, the UE 224 may transmit a reporting messageto its serving base station 210 indicating this condition. In response,the UE 224 may receive a handover command, and the UE may undergo ahandover to the cell 206.

In a network configured for UL-based mobility, UL reference signals fromeach UE may be utilized by the network to select a serving cell for eachUE. In some examples, the base stations 210, 212, and 214/216 maybroadcast unified synchronization signals (e.g., unified PrimarySynchronization Signals (PSSs), unified Secondary SynchronizationSignals (SSSs) and unified Physical Broadcast Channels (PBCH)). The UEs222, 224, 226, 228, 230, and 232 may receive the unified synchronizationsignals, derive the carrier frequency and slot timing from thesynchronization signals, and in response to deriving timing, transmit anuplink pilot or reference signal. The uplink pilot signal transmitted bya UE (e.g., UE 224) may be concurrently received by two or more cells(e.g., base stations 210 and 214/216) within the radio access network200. Each of the cells may measure a strength of the pilot signal, andthe radio access network (e.g., one or more of the base stations 210 and214/216 and/or a central node within the core network) may determine aserving cell for the UE 224. As the UE 224 moves through the radioaccess network 200, the network may continue to monitor the uplink pilotsignal transmitted by the UE 224. When the signal strength or quality ofthe pilot signal measured by a neighboring cell exceeds that of thesignal strength or quality measured by the serving cell, the network 200may handover the UE 224 from the serving cell to the neighboring cell,with or without informing the UE 224.

Although the synchronization signal transmitted by the base stations210, 212, and 214/216 may be unified, the synchronization signal may notidentify a particular cell, but rather may identify a zone of multiplecells operating on the same frequency and/or with the same timing. Theuse of zones in 5G networks or other next generation communicationnetworks enables the uplink-based mobility framework and improves theefficiency of both the UE and the network, since the number of mobilitymessages that need to be exchanged between the UE and the network may bereduced.

In various implementations, the air interface in the radio accessnetwork 200 may utilize licensed spectrum, unlicensed spectrum, orshared spectrum. Licensed spectrum provides for exclusive use of aportion of the spectrum, generally by virtue of a mobile networkoperator purchasing a license from a government regulatory body.Unlicensed spectrum provides for shared use of a portion of the spectrumwithout need for a government-granted license. While compliance withsome technical rules is generally still required to access unlicensedspectrum, generally, any operator or device may gain access. Sharedspectrum may fall between licensed and unlicensed spectrum, whereintechnical rules or limitations may be required to access the spectrum,but the spectrum may still be shared by multiple operators and/ormultiple RATs. For example, the holder of a license for a portion oflicensed spectrum may provide licensed shared access (LSA) to share thatspectrum with other parties, e.g., with suitable licensee-determinedconditions to gain access.

The air interface in the radio access network 200 may utilize one ormore duplexing algorithms Duplex refers to a point-to-pointcommunication link where both endpoints can communicate with one anotherin both directions. Full duplex means both endpoints can simultaneouslycommunicate with one another. Half duplex means only one endpoint cansend information to the other at a time. In a wireless link, a fullduplex channel generally relies on physical isolation of a transmitterand receiver, and suitable interference cancellation technologies. Fullduplex emulation is frequently implemented for wireless links byutilizing frequency division duplex (FDD) or time division duplex (TDD).In FDD, transmissions in different directions operate at differentcarrier frequencies. In TDD, transmissions in different directions on agiven channel are separated from one another using time divisionmultiplexing. That is, at some times the channel is dedicated fortransmissions in one direction, while at other times the channel isdedicated for transmissions in the other direction, where the directionmay change very rapidly, e.g., several times per slot.

In order for transmissions over the radio access network 200 to obtain alow block error rate (BLER) while still achieving very high data rates,channel coding may be used. That is, wireless communication maygenerally utilize a suitable error correcting block code. In a typicalblock code, an information message or sequence is split up into codeblocks (CBs), and an encoder (e.g., a CODEC) at the transmitting devicethen mathematically adds redundancy to the information message. Forexample, a transmitting device may transmit a transport block (TB) thatincludes multiple CBs grouped into different code block groups.Exploitation of this redundancy in the encoded information message canimprove the reliability of the message, enabling correction for any biterrors that may occur due to the noise.

In early 5G NR specifications, user data is coded using quasi-cycliclow-density parity check (LDPC) with two different base graphs: one basegraph is used for large code blocks and/or high code rates, while theother base graph is used otherwise. Control information and the physicalbroadcast channel (PBCH) are coded using Polar coding, based on nestedsequences. For these channels, puncturing, shortening, and repetitionare used for rate matching.

However, those of ordinary skill in the art will understand that aspectsof the present disclosure may be implemented utilizing any suitablechannel code. Various implementations of scheduling entities 108 andscheduled entities 106 may include suitable hardware and capabilities(e.g., an encoder, a decoder, and/or a CODEC) to utilize one or more ofthese channel codes for wireless communication.

The air interface in the radio access network 200 may utilize one ormore multiplexing and multiple access algorithms to enable simultaneouscommunication of the various devices. For example, 5G NR specificationsprovide multiple access for UL transmissions from UEs 222 and 224 tobase station 210, and for multiplexing for DL transmissions from basestation 210 to one or more UEs 222 and 224, utilizing orthogonalfrequency division multiplexing (OFDM) with a cyclic prefix (CP). Inaddition, for UL transmissions, 5G NR specifications provide support fordiscrete Fourier transform-spread-OFDM (DFT-s-OFDM) with a CP (alsoreferred to as single-carrier FDMA (SC-FDMA)). However, within the scopeof the present disclosure, multiplexing and multiple access are notlimited to the above schemes, and may be provided utilizing timedivision multiple access (TDMA), code division multiple access (CDMA),frequency division multiple access (FDMA), sparse code multiple access(SCMA), resource spread multiple access (RSMA), or other suitablemultiple access schemes. Further, multiplexing DL transmissions from thebase station 210 to UEs 222 and 224 may be provided utilizing timedivision multiplexing (TDM), code division multiplexing (CDM), frequencydivision multiplexing (FUM), orthogonal frequency division multiplexing(OFDM), sparse code multiplexing (SCM), or other suitable multiplexingschemes.

Various aspects of the present disclosure will be described withreference to an OFDM waveform, schematically illustrated in FIG. 3. Itshould be understood by those of ordinary skill in the art that thevarious aspects of the present disclosure may be applied to aDFT-s-OFDMA waveform in substantially the same way as described hereinbelow. That is, while some examples of the present disclosure may focuson an OFDM link for clarity, it should be understood that the sameprinciples may be applied as well to DFT-s-OFDMA waveforms.

Within the present disclosure, a frame refers to a predeterminedduration (e.g., 10 ms) for wireless transmissions, with each frameconsisting of a predetermined number of frames (e.g., 10 subframes of 1ms each). On a given carrier, there may be one set of frames in the UL,and another set of frames in the DL. Referring now to FIG. 3, anexpanded view of an exemplary DL subframe 302 is illustrated, showing anOFDM resource grid 304. However, as those skilled in the art willreadily appreciate, the PHY transmission structure for any particularapplication may vary from the example described here, depending on anynumber of factors. Here, time is in the horizontal direction with unitsof OFDM symbols; and frequency is in the vertical direction with unitsof subcarriers or tones.

The resource grid 304 may be used to schematically representtime-frequency resources for a given antenna port. That is, in a MIMOimplementation with multiple antenna ports available, a correspondingmultiple number of resource grids 304 may be available forcommunication. The resource grid 304 is divided into multiple resourceelements (REs) 306. An RE, which is 1 subcarrier×1 symbol, is thesmallest discrete part of the time-frequency grid, and contains a singlecomplex value representing data from a physical channel or signal.Depending on the modulation utilized in a particular implementation,each RE may represent one or more bits of information. In some examples,a block of REs may be referred to as a physical resource block (PRB) ormore simply a resource block (RB) 408, which contains any suitablenumber of consecutive subcarriers in the frequency domain. In oneexample, an RB may include 12 subcarriers, a number independent of thenumerology used. In some examples, depending on the numerology, an RBmay include any suitable number of consecutive OFDM symbols in the timedomain. Within the present disclosure, it is assumed that a single RBsuch as the RB 308 entirely corresponds to a single direction ofcommunication (either transmission or reception for a given device).

A UE generally utilizes only a subset of the resource grid 304. An RBmay be the smallest unit of resources that can be allocated to a UE.Thus, the more RBs scheduled for a UE, and the higher the modulationscheme chosen for the air interface, the higher the data rate for theUE.

In this illustration, the RB 308 is shown as occupying less than theentire bandwidth of the subframe 302, with some subcarriers illustratedabove and below the RB 308. In a given implementation, the subframe 302may have a bandwidth corresponding to any number of one or more RBs 308.Further, in this illustration, the RB 308 is shown as occupying lessthan the entire duration of the subframe 302, although this is merelyone possible example.

Each 1 ms subframe 302 may consist of one or multiple adjacent slots. Inthe example shown in FIG. 3, one subframe 302 includes four slots 310,as an illustrative example. In some examples, a slot may be definedaccording to a specified number of OFDM symbols with a given cyclicprefix (CP) length. For example, a slot may include 7 or 14 OFDM symbolswith a nominal CP. Additional examples may include mini-slots having ashorter duration (e.g., one or two OFDM symbols). These mini-slots mayin some cases be transmitted occupying resources scheduled for ongoingslot transmissions for the same or for different UEs.

An expanded view of one of the slots 310 illustrates the slot 310including a control region 312 and a data region 314. In general, thecontrol region 312 may carry control channels (e.g., PDCCH), and thedata region 314 may carry data channels (e.g., PDSCH or PUSCH). Ofcourse, a slot may contain all DL, all UL, or at least one DL portionand at least one UL portion. The simple structure illustrated in FIG. 3is merely exemplary in nature, and different slot structures may beutilized, and may include one or more of each of the control region(s)and data region(s).

Although not illustrated in FIG. 3, the various REs 306 within a RB 308may be scheduled to carry one or more physical channels, includingcontrol channels, shared channels, data channels, etc. Other REs 306within the RB 308 may also carry pilots or reference signals, includingbut not limited to a demodulation reference signal (DMRS) a controlreference signal (CRS), or a sounding reference signal (SRS). Thesepilots or reference signals may provide for a receiving device toperform channel estimation of the corresponding channel, which mayenable coherent demodulation/detection of the control and/or datachannels within the RB 308.

In a DL transmission, the transmitting device (e.g., the schedulingentity 108) may allocate one or more REs 306 (e.g., within a controlregion 312) to carry DL control information 114 including one or more DLcontrol channels, such as a PBCH; a PSS; a SSS; a physical controlformat indicator channel (PCFICH); a physical hybrid automatic repeatrequest (HARQ) indicator channel (PHICH); and/or a physical downlinkcontrol channel (PDCCH), etc., to one or more scheduled entities 106.The PCFICH provides information to assist a receiving device inreceiving and decoding the PDCCH. The PDCCH carries downlink controlinformation (DCI) including but not limited to power control commands,scheduling information, a grant, and/or an assignment of REs for DL andUL transmissions. The PHICH carries HARQ feedback transmissions such asan acknowledgment (ACK) or negative acknowledgment (NACK). HARQ is atechnique well-known to those of ordinary skill in the art, wherein theintegrity of packet transmissions may be checked at the receiving sidefor accuracy, e.g., utilizing any suitable integrity checking mechanism,such as a checksum or a cyclic redundancy check (CRC). If the integrityof the transmission confirmed, an ACK may be transmitted, whereas if notconfirmed, a NACK may be transmitted. In response to a NACK, thetransmitting device may send a HARQ retransmission, which may implementchase combining, incremental redundancy, etc.

In an UL transmission, the transmitting device (e.g., the scheduledentity 106) may utilize one or more REs 306 to carry UL controlinformation 118 including one or more UL control channels, such as aphysical uplink control channel (PUCCH), to the scheduling entity 108.UL control information may include a variety of packet types andcategories, including pilots, reference signals, and informationconfigured to enable or assist in decoding uplink data transmissions. Insome examples, the control information 118 may include a schedulingrequest (SR), e.g., a request for the scheduling entity 108 to scheduleuplink transmissions. Here, in response to the SR transmitted on thecontrol channel 118, the scheduling entity 108 may transmit downlinkcontrol information 114 that may schedule resources for uplink packettransmissions. UL control information may also include HARQ feedback,channel state feedback (CSF), or any other suitable UL controlinformation.

In addition to control information, one or more REs 306 (e.g., withinthe data region 314) may be allocated for user data or traffic data.Such traffic may be carried on one or more traffic channels, such as,for a DL transmission, a physical downlink shared channel (PDSCH); orfor an UL transmission, a physical uplink shared channel (PUSCH). Insome examples, one or more REs 306 within the data region 314 may beconfigured to carry system information blocks (SIBs), carryinginformation that may enable access to a given cell.

The channels or carriers described above and illustrated in FIGS. 1 and2 are not necessarily all the channels or carriers that may be utilizedbetween a scheduling entity 108 and scheduled entities 106, and those ofordinary skill in the art will recognize that other channels or carriersmay be utilized in addition to those illustrated, such as other traffic,control, and feedback channels.

These physical channels described above are generally multiplexed andmapped to transport channels for handling at the medium access control(MAC) layer. Transport channels carry blocks of information calledtransport blocks (TB). The transport block size (TBS), which maycorrespond to a number of bits of information, may be a controlledparameter, based on the modulation and coding scheme (MCS) and thenumber of resource blocks (RBs) in a given transmission.

In a 5G NR network, a transport block (TB) may include multiple codeblocks (CBs), which may be grouped or arranged into multiple code blockgroups. A code block group (CBG) may include one or more CBs. FIG. 4 isa block diagram conceptually illustrating an exemplary TB 400 accordingto some aspects of the disclosure. The TB 400 includes a plurality ofCBs (e.g., CB1, CB2, CB3, . . . CB9 are illustrated in FIG. 4). In otherexamples, the TB 400 may have more or fewer CBs. The CBs may be groupedinto different CBGs (e.g., three CBGs 402 are shown in FIG. 4). In someexamples, a CBG may include one CB, all CBs, or any number of CBs in aTB. When one or more CBs are not successfully transmitted to a receiver,more efficient HARQ retransmission may be achieved by retransmittingonly the CBG(s) containing the desired CBs, instead of the entire TB. Insome aspects of the disclosure, the scheduling entity may use differentCBG designs or arrangements for different UEs or scheduled entities.

FIG. 5 is a diagram illustrating an uplink (UL) centric slot 500 forwireless communication according to some aspects of the disclosure. Insome examples, an UL-centric slot 500 may be utilized for UL datacommunication between a scheduling entity 108 (e.g., base station, eNB,gNB) and one or more scheduled entities 106 (e.g., UE), or between anydevices illustrated in FIGS. 1-2 and/or 6. Multiple UEs can share theUL-centric slot 500. For example, the bandwidth of the slot may beallocated to three UEs (illustrated as UE0, UE1, and UE2) in a frequencydivision manner. In other examples, the UL-centric slot 500 may beshared by more or fewer UEs. The subbands allocated to the UEs may havethe same bandwidth or different bandwidths. The UL-centric slot 500 hasa DL control portion 502 and an UL data portion 504 that are separatedby a gap 506 or guard period. The guard period can provide time for theUEs to switch or reconfigure their circuitry (e.g., RF chain) between areceiving mode and a transmitting mode. The DL control portion 502 maycarry scheduling assignments and other control information. For example,the DL control portion 502 may include a PDCCH that provides variousinformation such as DCI.

In some aspects of the disclosure, the DL control portion 502 (e.g.,DCI) may provide a CBG failure mask and CBG-based HARQ feedback forfacilitating CB HARQ retransmission in CBG unit.

The UL data portion 504 carries UL payload or user data (e.g., PUSCH)for one or more UEs (e.g., UE0, UE1, UE2). The UL data may correspond toa transport block (TB) that is mapped to a number of time-domain symbols(e.g., OFDM symbols). For example, in FIG. 5, the horizontal directionof the UL-centric slot 500 corresponds to the time domain. In 5G NR, aTB may include a predetermined number of code blocks (e.g., 61 CBs) thatare encoded and mapped to the transmitted time domain symbols. The CBsof each PUSCH are arranged into CBGs as illustrated in the example ofFIG. 4. The CBs may not be aligned with the OFDM symbols. In that case,a code block (CB) may ride across symbol boundary. Each UL data portion504 or PUSCH can include different number of CBGs, and the CBGs may havedifferent sizes (i.e., different number of CBs). For example, the PUSCHsof UE0, UE1, and UE2 may carry different CBGs and/or CBs.

In some cases, a bursty interference pattern 508 may interfere with thetransmission of some symbols of the UL-centric slot 500. A burstyinterference pattern may have a duration significantly shorter than theUL-centric slot. In this case, all UEs sharing the slot may experiencesimilar interference that causes CBG decoding failures at similar CBGlocations (e.g., in time domain locations). The bursty interference maybe caused, for example, by URLLC traffic or other high priority burstytraffic from other UEs, URLLC traffic of other gNBs, and/or other burstyinterference from other nodes in the system.

In CBG-based HARQ retransmission, HARQ retransmission is performed basedon CBG units, instead of the entire TB. Therefore, only the CBG that hasdecoding errors may be retransmitted. To that end, the scheduling entity108 (e.g., gNB) may transmit a CBG bitmap or mask (e.g., CBG NACK) in aDCI for each error CBG for each UE. The CBG bitmap indicates the CBG(s)that need to be retransmitted. However, if the scheduling entitytransmits separate DCI to each UE for the CBGs to be retransmitted,there may be significant signaling control overhead. Therefore, it isbeneficial to reduce the signaling overhead of CBG-based HARQretransmissions.

FIG. 6 is a diagram illustrating a CBG-based HARQ process utilizing aCBG failure mask according to some aspects of the disclosure. Asdescribed below, some or all illustrated features may be omitted in aparticular implementation within the scope of the present disclosure,and some illustrated features may not be required for implementation ofall embodiments. Referring to FIG. 6, a scheduling entity (e.g., gNB602) may be in wireless communication with a number of scheduledentities 604 (e.g., UE1, UE2, UE3). The gNB 602 may be the schedulingentity 108, and the UEs 604 may be the scheduled entities 106illustrated in FIG. 1.

The UEs 604 (e.g., UE1, UE2, UE3) may share an UL-centric slot totransmit UL data 606 to the gNB 602. For example, the UL slot may be thesame as the UL-centric slot 500 described in relation to FIG. 5. In thiscase, each UE's PUSCH 606 may be allocated to a different bandwidth orsubband. The gNB 602 receives and decodes the PUSCHs from each UE andidentifies any CBG that has a decoding error. For example, the decodingerror may be caused by a bursty interference pattern similar to thebursty interference 508 shown in FIG. 5. In that case, the UEs mayexperience similar interference to their CBGs in similar locations(e.g., time-domain symbols) of the slot. Based on the decoding errors,if any, the gNB can determine the CBGs that need to be retransmitted ina CBG-based HARQ process from one or more of the UEs. To that end, thegNB may transmit CBG NACKs to the UEs.

FIG. 7 is a diagram illustrating an exemplary process for generating aCBG failure mask according to some aspects of the disclosure. At block702, the gNB determines the error CBG(s) of UE0. At block 704, the gNBdetermines the error CBG(s) of UE1. At block 706, the gNB determines theerror CBG(s) of UE2. An error CBG is a CBG that includes at least one CBthat is not received and/or decoded successfully by the receiver. Theprocess of FIG. 7 may be adapted to generate a CBG failure mask of moreor fewer UEs. At block 708, the gNB generates a CBG failure mask thatcaptures all the CBG NACKs for the UEs 604. In some examples, the CBGfailure mask may indicate the UL resource or symbols corresponding tothe CBGs with decoding errors. Based on the information of the CBGfailure mask, each UE can determine the corresponding CBG(s) to beretransmitted using a CBG-based HARQ process. Referring back to FIG. 6,the gNB may transmit the CBG failure mask to the UEs, for example, in agroup DCI 610 that is in a common or group search space of the UEs. Thesearch space indicates the set of control channel elements locationswhere the UE may find its DL control channel (e.g., PDCCH). Each controlchannel element (CCE) includes a certain number of resource elementgroups, and one resource element group (REG) corresponds to a certainnumber of resource elements. Signaling overhead may be reduced by usingthe group DCI.

In some examples, the transmission timing of the CBG failure mask may befixed with respect to the PUSCH transmission. In another example, thetransmission timing of the CBG failure mask may be flexible. In thatcase, the group DCI 610 may include an index or value to indicate thecorresponding PUSCH slot.

In some aspects of the disclosure, with reference to FIG. 8, at block802 each UE 604 monitors the common search space for the group DCI 610.Once a group DCI 610 is received, at block 804 the UE compares the CBGfailure mask with its CBG structure to determine which CBGs or CBs, ifany, need to be retransmitted. If the CBG failure mask covers one ormore CBGs of the UE, at block 806 the UE may transmit the CBG(s) using aHARQ retransmission process; otherwise, at block 808 the UE does notretransmit any CBG.

FIG. 9 is a diagram illustrating an exemplary CBG failure mask for anUL-centric slot 900 according to some aspects of the disclosure. The CBGfailure mask 902 is common across all UEs (e.g., UE0, UE1, UE2). Basedon the CBG failure mask 902, each UE can determine its CBG(s) 904 thatneed to be retransmitted due to bursty interference 906. The CBGs 904 tobe retransmitted may be different in size and/or location among the UEs.

Referring back to FIG. 6, the gNB 602 may transmit a unicast ULretransmission grant 614 (e.g., another DCI) to each UE 604 to triggerCBG retransmission. If a UE has no CBG decoding error or CBG NACK, thegNB 602 may not transmit a retransmission grant to this particular UE.In some aspects of the disclosure, the group DCI 610 with the CBGfailure mask may or may not be transmitted in the same slot as the ULretransmission grant 614. However, the group DCI 610 is transmitted nolater than the UL retransmission grant 614.

In some aspects of the disclosure, the retransmission grant DCI 614 mayinclude a bit, flag, or value to indicate whether the retransmissiongrant follows a CBG failure mask or not. If it indicates that theretransmission grant does not follow a CBG failure mask, the UE mayperform HARQ retransmission at the TB level.

In some examples, different PUSCHs or UL data from different UEs mayhave very different interference patterns. It may be the case when theinterference affects one or more subbands, but not the entire bandwidth.For example, with reference to FIG. 10, the bursty interference 1002affects the PUSCHs of UE0 and UE1, but not UE2. In that case, UEsscheduled on different subbands may experience different CBGinterference patterns. If a CBG failure mask covers the entirebandwidth, the mask may become too wide and cause a lot number of CBGsto be retransmitted unnecessarily. In this example, the CBG failure mask1004 may cover only the bandwidth of UE0 and UE1.

It some examples, some UEs in a cell may not be affected by burstyinterference, especially when the interference comes from a neighborcell. In that case, some UE near that neighbor cell may be affectedwhile other UEs further away from that cell may not be affected. The UEsthat are not affected may be signaled differently such that they may notfollow the CBG failure mask. For example, the gNB may not transmit theCBG failure mask to these UEs.

In some aspects of the disclosure, multiple CBG failure masks may beused to handle scenarios in which the UEs experience substantiallydifferent interference patterns. In one example, the gNB may transmitmultiple CBG failure masks in separate DCIs. A UE can be configured tomonitor one or multiple DCIs. For example, a UE may monitor one CBGfailure mask DCI and generates the CBG retransmission set based on themonitored DCI. In another example, a UE may monitor multiple CBG failuremask DCIs, and the retransmission grant DCI may indicate which one ofthe CBG failure mask to use to generate the CBG retransmission set.Because the gNB is aware of the CBG error pattern of the UE, the gNB candirect the UE to a CBG failure mask to minimize the retransmittedCBG(s).

In another example, multiple CBG failure masks may be included in thesame CBG failure mask DCI. In the UL retransmission DCI grant, the gNBcan indicate to the UE which mask out of the many to be used.Alternatively, the masks can be configured to be subband dependent, andthe UE can pick the mask(s) based on its PUSCH subband(s).

FIG. 11 is a block diagram illustrating an example of a hardwareimplementation for a scheduling entity 1100 employing a processingsystem 1114. For example, the scheduling entity 1100 may be a userequipment (UE) as illustrated in any one or more of FIGS. 1, 2, and/or6. In another example, the scheduling entity 1100 may be a base stationas illustrated in any one or more of FIGS. 1, 2, and/or 6.

The scheduling entity 1100 may be implemented with a processing system1114 that includes one or more processors 1104. Examples of processors1104 include microprocessors, microcontrollers, digital signalprocessors (DSPs), field programmable gate arrays (FPGAs), programmablelogic devices (PLDs), state machines, gated logic, discrete hardwarecircuits, and other suitable hardware configured to perform the variousfunctionality described throughout this disclosure. In various examples,the scheduling entity 1100 may be configured to perform any one or moreof the functions described herein. That is, the processor 1104, asutilized in a scheduling entity 1100, may be used to implement any oneor more of the processes and procedures described in relation to FIGS.4-10 and 12.

In this example, the processing system 1114 may be implemented with abus architecture, represented generally by the bus 1102. The bus 1102may include any number of interconnecting buses and bridges depending onthe specific application of the processing system 1114 and the overalldesign constraints. The bus 1102 communicatively couples togethervarious circuits including one or more processors (represented generallyby the processor 1104), a memory 1105, and computer-readable media(represented generally by the computer-readable medium 1106). The bus1102 may also link various other circuits such as timing sources,peripherals, voltage regulators, and power management circuits, whichare well known in the art, and therefore, will not be described anyfurther. A bus interface 1108 provides an interface between the bus 1102and a transceiver 1110. The transceiver 1110 provides a communicationinterface or means for communicating with various other apparatus over atransmission medium. Depending upon the nature of the apparatus, a userinterface 1112 (e.g., keypad, display, speaker, microphone, joystick)may also be provided. Of course, such a user interface 1112 is optional,and may be omitted in some examples, such as a base station.

In some aspects of the disclosure, the processor 1104 may includecircuitry (e.g., a processing circuit 1140, a communication circuit1142, and a HARQ circuit 1144) configured for various functions,including, for example, CBG based HARQ retransmission. For example, thecircuitry may be configured to implement one or more of the functionsand processes described in relation to FIG. 12.

The processor 1104 is responsible for managing the bus 1102 and generalprocessing, including the execution of software stored on thecomputer-readable medium 1106. The software, when executed by theprocessor 1104, causes the processing system 1114 to perform the variousfunctions described below for any particular apparatus. Thecomputer-readable medium 1106 and the memory 1105 may also be used forstoring data that is manipulated by the processor 1104 when executingsoftware.

One or more processors 1104 in the processing system may executesoftware. Software shall be construed broadly to mean instructions,instruction sets, code, code segments, program code, programs,subprograms, software modules, applications, software applications,software packages, routines, subroutines, objects, executables, threadsof execution, procedures, functions, etc., whether referred to assoftware, firmware, middleware, microcode, hardware descriptionlanguage, or otherwise. The software may reside on a computer-readablemedium 1106. The computer-readable medium 1106 may be a non-transitorycomputer-readable medium. A non-transitory computer-readable mediumincludes, by way of example, a magnetic storage device (e.g., hard disk,floppy disk, magnetic strip), an optical disk (e.g., a compact disc (CD)or a digital versatile disc (DVD)), a smart card, a flash memory device(e.g., a card, a stick, or a key drive), a random access memory (RAM), aread only memory (ROM), a programmable ROM (PROM), an erasable PROM(EPROM), an electrically erasable PROM (EEPROM), a register, a removabledisk, and any other suitable medium for storing software and/orinstructions that may be accessed and read by a computer. Thecomputer-readable medium 1106 may reside in the processing system 1114,external to the processing system 1114, or distributed across multipleentities including the processing system 1114. The computer-readablemedium 1106 may be embodied in a computer program product. By way ofexample, a computer program product may include a computer-readablemedium in packaging materials. Those skilled in the art will recognizehow best to implement the described functionality presented throughoutthis disclosure depending on the particular application and the overalldesign constraints imposed on the overall system.

In one or more examples, the computer-readable storage medium 1106 mayinclude software (e.g., processing instructions 1152, communicationinstructions 1154, and HARQ instructions 1156) configured for variousfunctions, including, for example, CBG based HARQ retransmission. Forexample, the software may be configured to implement one or more of thefunctions described in relation to FIG. 12.

FIG. 12 is a flow chart illustrating an exemplary process 1200 forwireless communication at a scheduling entity utilizing a CBG failuremask according to some aspects of the disclosure. As described below,some or all illustrated features may be omitted in a particularimplementation within the scope of the present disclosure, and someillustrated features may not be required for implementation of allembodiments. In some examples, the process 1200 may be carried out bythe scheduling entity 108 and/or scheduled entity 106 illustrated inFIG. 1. In some examples, the process 1200 may be carried out by anysuitable apparatus or means for carrying out the functions or algorithmdescribed below.

At block 1202, with reference to FIG. 11, a scheduling entity 1100utilizes a communication circuit 1142 and a transceiver 1110 to receivea first UL transmission including a plurality of first CBGs from a firstUE and a second UL transmission comprising a plurality of second CBGsfrom a second UE. For example, the first and second UEs may any UEsillustrated in FIG. 6. In one example, the first UL transmission andsecond UL transmission may be the PUSCHs 606 illustrated in FIG. 6.

At block 1204, the scheduling entity 1100 utilizes a processing circuit1140 to determine decoding error in one or more CBGs among the pluralityof first and second CBGs. For example, the decoding error of the CBGsmay be caused by a bursty interference pattern (e.g., burstyinterference 508 shown in FIG. 5). Decoding error may occur when thescheduled entity failed to receive and/or decode the UL transmission torecover the transmitted data carried by the CBGs.

At block 1206, the scheduling entity utilizes a HARQ circuit 1144 togenerate a CBG failure mask that indicates the decoding error of theCBGs. The CBG failure mask may include a time-frequency domain region(e.g., one or more time-frequency resource elements) that are designedfor CBG based retransmission. For example, the CBG failure mask mayinclude multiple bits or a bitmap that indicates the time-frequencydomain region or CBGs that have decoding error for both the first UE andsecond UE.

At block 1208, the scheduling entity utilizes the communication circuit1142 and transceiver 1110 to transmit the CBG failure mask to the firstUE and the second UE to facilitate retransmission of the CBGs indicatedby the CBG failure mask. In one example, the CBG failure mask may beincluded in a group DCI destined to the first UE and second UE. Thescheduling entity may transmit the DCI containing the CBG failure maskusing a PDCCH in a common search space that is monitored by both firstUE and second UE. Using the CBG failure mask, the scheduling entity maysignal the CBG errors to multiple UEs in a single DCI, and hencereducing signaling overhead.

Although the above exemplary process 1200 has been described using twoUEs, the process may be modified and adapted for more UEs according toother aspects of the present disclosure. In some examples, thescheduling entity may transmit multiple CBG failure mask DCIs fordifferent subbands or different groups of UEs.

FIG. 13 is a conceptual diagram illustrating an example of a hardwareimplementation for an exemplary scheduled entity 1300 employing aprocessing system 1314. In accordance with various aspects of thedisclosure, an element, or any portion of an element, or any combinationof elements may be implemented with a processing system 1314 thatincludes one or more processors 1304. For example, the scheduled entity1300 may be a user equipment (UE) as illustrated in any one or more ofFIGS. 1, 2, and/or 6.

The processing system 1314 may be substantially the same as theprocessing system 1114 illustrated in FIG. 11, including a bus interface1308, a bus 1302, memory 1305, a processor 1304, and a computer-readablemedium 1306. Furthermore, the scheduled entity 1300 may include a userinterface 1312 and a transceiver 1310 substantially similar to thosedescribed above in FIG. 11. That is, the processor 1304, as utilized ina scheduled entity 1300, may be used to implement any one or more of theprocesses described in relation to FIGS. 6-9 and 14.

In some aspects of the disclosure, the processor 1304 may includecircuitry (e.g., a processing circuit 1340, a communication circuit1342, a HARQ circuit 1344) configured for various functions, including,for example, CBG based HARQ retransmission. For example, the circuitrymay be configured to implement one or more of the functions described inrelation to FIG. 14. In one or more examples, the computer-readablestorage medium 1306 may include software (e.g., processing instructions1352, communication instructions 1354, and HARQ instructions 1356)configured for various functions, including, for example, CBG based HARQretransmission. For example, the software may be configured to implementone or more of the functions described in relation to FIG. 14.

FIG. 14 is a flow chart illustrating an exemplary process 1400 forwireless communication at a UE utilizing a CBG failure mask according tosome aspects of the disclosure. As described below, some or allillustrated features may be omitted in a particular implementationwithin the scope of the present disclosure, and some illustratedfeatures may not be required for implementation of all embodiments. Insome examples, the process 1400 may be carried out by the schedulingentity 108 and/or scheduled entity 106 illustrated in FIG. 1. In someexamples, the process 1400 may be carried out by any suitable apparatusor means for carrying out the functions or algorithm described below.

At block 1402, with reference to FIG. 13, a first UE utilizes acommunication circuit 1342 and a transceiver 1310 to transmit an ULtransmission to a scheduling entity (e.g., gNB). The UL transmissioncarries a plurality of CBGs. In one example, the first UE may be one ofthe UEs in FIG. 6.

At block 1404, the first UE utilizes the communication circuit 1342 toreceive a CBG failure mask from the scheduled entity, and the CBGfailure mask includes a time-frequency domain region (e.g., one or moretime-frequency resource elements) designed for CBG retransmission. TheCBG failure mask may be similar to that shown in FIG. 9 or 10. That is,the CBGs of the UL transmission within the time-frequency domain regionmay have decoding error and need to be retransmitted. For example, thedecoding error of the CBGs may be caused by a bursty interferencepattern similar to that shown in FIG. 5.

At block 1406, the UE compares the time-frequency resources of thetransmitted CBGs with the time-frequency resources in the CBG failuremask, to determine one or more of the CBGs for retransmission. The UEmay utilize the HARQ circuit 1344 to determine the CBGs forretransmission.

At block 1408, after receiving an UL grant from the scheduling entity,the UE can transmit the one or more CBGs for retransmission as indicatedby the CBG failure mask. Using the CBG failure mask, the schedulingentity can indicate CBG decoding error of multiple UEs using a singleDCI (e.g., group DCI). Using the above described processes, CBG basedHARQ retransmission efficiency may be increased, and signaling overheadmay be reduced.

In one configuration, the apparatus 1100 and/or 1300 for wirelesscommunication includes means for performing various functions andprocesses described in relation to FIGS. 5-10,12, and 14. In one aspect,the aforementioned means may be the processor 1104 and/or 1304 in whichthe invention resides in FIGS. 5-10, 12, and 14, configured to performthe functions recited by the aforementioned means. In another aspect,the aforementioned means may be a circuit or any apparatus configured toperform the functions recited by the aforementioned means.

Of course, in the above examples, the circuitry included in theprocessor 1304 and/or 1404 is merely provided as an example, and othermeans for carrying out the described functions may be included withinvarious aspects of the present disclosure, including but not limited tothe instructions stored in the computer-readable storage medium 1306and/or 1406, or any other suitable apparatus or means described in anyone of the FIGS. 1, 2, and/or 6, and utilizing, for example, theprocesses and/or algorithms described herein in relation to FIGS. 5-10,12, and 14.

Several aspects of a wireless communication network have been presentedwith reference to an exemplary implementation. As those skilled in theart will readily appreciate, various aspects described throughout thisdisclosure may be extended to other telecommunication systems, networkarchitectures and communication standards.

By way of example, various aspects may be implemented within othersystems defined by 3GPP, such as Long-Term Evolution (LTE), the EvolvedPacket System (EPS), the Universal Mobile Telecommunication System(UMTS), and/or the Global System for Mobile (GSM). Various aspects mayalso be extended to systems defined by the 3rd Generation PartnershipProject 2 (3GPP2), such as CDMA2000 and/or Evolution-Data Optimized(EV-DO). Other examples may be implemented within systems employing IEEE802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Ultra-Wideband (UWB),Bluetooth, and/or other suitable systems. The actual telecommunicationstandard, network architecture, and/or communication standard employedwill depend on the specific application and the overall designconstraints imposed on the system.

Within the present disclosure, the word “exemplary” is used to mean“serving as an example, instance, or illustration.” Any implementationor aspect described herein as “exemplary” is not necessarily to beconstrued as preferred or advantageous over other aspects of thedisclosure. Likewise, the term “aspects” does not require that allaspects of the disclosure include the discussed feature, advantage ormode of operation. The term “coupled” is used herein to refer to thedirect or indirect coupling between two objects. For example, if objectA physically touches object B, and object B touches object C, thenobjects A and C may still be considered coupled to one another—even ifthey do not directly physically touch each other. For instance, a firstobject may be coupled to a second object even though the first object isnever directly physically in contact with the second object. The terms“circuit” and “circuitry” are used broadly, and intended to include bothhardware implementations of electrical devices and conductors that, whenconnected and configured, enable the performance of the functionsdescribed in the present disclosure, without limitation as to the typeof electronic circuits, as well as software implementations ofinformation and instructions that, when executed by a processor, enablethe performance of the functions described in the present disclosure.

One or more of the components, steps, features and/or functionsillustrated in FIGS. 1-14 may be rearranged and/or combined into asingle component, step, feature or function or embodied in severalcomponents, steps, or functions. Additional elements, components, steps,and/or functions may also be added without departing from novel featuresdisclosed herein. The apparatus, devices, and/or components illustratedin FIGS. 1-14 may be configured to perform one or more of the methods,features, or steps described herein. The novel algorithms describedherein may also be efficiently implemented in software and/or embeddedin hardware.

It is to be understood that the specific order or hierarchy of steps inthe methods disclosed is an illustration of exemplary processes. Basedupon design preferences, it is understood that the specific order orhierarchy of steps in the methods may be rearranged. The accompanyingmethod claims present elements of the various steps in a sample order,and are not meant to be limited to the specific order or hierarchypresented unless specifically recited therein.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. Variousmodifications to these aspects will be readily apparent to those skilledin the art, and the generic principles defined herein may be applied toother aspects. Thus, the claims are not intended to be limited to theaspects shown herein, but are to be accorded the full scope consistentwith the language of the claims, wherein reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.” Unless specifically statedotherwise, the term “some” refers to one or more. A phrase referring to“at least one of” a list of items refers to any combination of thoseitems, including single members. As an example, “at least one of: a, b,or c” is intended to cover: a; b; c; a and b; a and c; b and c; and a, band c. All structural and functional equivalents to the elements of thevarious aspects described throughout this disclosure that are known orlater come to be known to those of ordinary skill in the art areexpressly incorporated herein by reference and are intended to beencompassed by the claims. Moreover, nothing disclosed herein isintended to be dedicated to the public regardless of whether suchdisclosure is explicitly recited in the claims. No claim element is tobe construed under the provisions of 35 U.S.C. § 112(f) unless theelement is expressly recited using the phrase “means for” or, in thecase of a method claim, the element is recited using the phrase “stepfor.”

What is claimed is:
 1. A method of wireless communication operable at a scheduling entity, comprising: receiving a first uplink (UL) transmission comprising a plurality of first code block groups (CBGs) from a first user equipment (UE) and a second UL transmission comprising a plurality of second CBGs from a second UE; determining decoding error in one or more CBGs among the first and second CBGs; generating a CBG failure mask indicating the decoding error, the CBG failure mask configured to indicate one or more time-frequency domain regions covering the one or more CBGs with the decoding error; and transmitting the CBG failure mask to the first UE and the second UE to facilitate retransmission of the CBGs indicated by the CBG failure mask.
 2. The method of claim 1, wherein one or more CBGs from the first UE are different in sizes from one or more CBGs from the second UE.
 3. The method of claim 1, wherein the receiving comprises: receiving the first UL transmission in a first subband; and receiving the second UL transmission in a second subband that is different from the first subband.
 4. The method of claim 1, further comprising: transmitting a first retransmission grant to the first UE; and transmitting a second retransmission grant, separated from the first retransmission grant, to the second UE, wherein the CBG failure mask is transmitted in a first slot, and wherein the first retransmission grant or the second retransmission grant is transmitted in the first slot or a later slot.
 5. The method of claim 4, wherein the first retransmission grant and the second retransmission grant are configured to indicate at least one of the existence or location of the corresponding CBG failure mask.
 6. The method of claim 1, wherein the transmitting comprises: transmitting the CBG failure mask in a common search space of the first UE and the second UE.
 7. The method of claim 1, wherein the CBG failure mask comprises a first CBG failure mask used by the first UE and a second CBG failure mask used by the second UE.
 8. The method of claim 7, further comprising: transmitting a first retransmission grant to the first UE, wherein the first retransmission grant signals the first UE to utilize the first CBG failure mask, wherein the first CBG failure mask is associated with a first subband for transmitting the first UL transmission; and transmitting a second retransmission grant to the second UE, wherein the second retransmission grant signals the second UE to utilize the second CBG failure mask, wherein the second CBG failure mask is associated with a second subband for transmitting the second UL transmission.
 9. The method of claim 1, wherein the transmitting comprises: transmitting a first CBG failure mask in a first control message to a first set of UEs including the first UE; and transmitting a second CBG failure mask in a second control message to a second set of UEs including the second UE.
 10. The method of claim 9, further comprising: transmitting a first retransmission grant to signal the first UE to utilize the first CBG failure mask; and transmitting a second retransmission grant to signal the second UE to utilize the second CBG failure mask.
 11. A method of wireless communication operable at a first user equipment (UE), comprising: transmitting an uplink (UL) transmission to a scheduling entity, the UL transmission carrying a plurality of code block groups (CBGs); receiving a CBG failure mask from the scheduling entity, the CBG failure mask comprising a time-frequency domain region designated for CBG retransmission; comparing time-frequency resources of the transmitted CBGs with time-frequency resources in the time-frequency domain region of the CBG failure mask, to determine one or more of the CBGs for retransmission; and transmitting the one or more CBGs for retransmission.
 12. The method of claim 11, wherein the transmitting the UL transmission comprises: transmitting the UL transmission in a first subband that is different from a second subband allocated to a second UE that receives the same CBG failure mask.
 13. The method of claim 11, further comprising: receiving a first retransmission grant, separated from a second retransmission grant for a second UE, from the scheduling entity, wherein the CBG failure mask comprises a first CBG failure mask for the first UE and a second CBG failure mask for the second UE, wherein the first retransmission grant signals the first UE to utilize the first CBG failure mask for CBG retransmission using a CBG based retransmission process, and wherein the second retransmission grant signals the second UE to utilize the second CBG failure mask for CBG retransmission using a CBG based retransmission process.
 14. The method of claim 13, wherein the CBG failure mask is received in a first slot, and wherein the first retransmission grant is received in the first slot or a second slot later than the first slot.
 15. The method of claim 11, wherein the receiving comprises: receiving the CBG failure mask in a common search space of the first UE and a second UE that receives the same CBG failure mask.
 16. A scheduling entity, comprising: a communication interface configured to communicate with a first user equipment (UE) and a second UE; a memory; and a processor operatively coupled to the communication interface and the memory, wherein the processor and the memory are configured to: receive a first uplink (UL) transmission comprising a plurality of first code block groups (CBGs) from the first UE and a second UL transmission comprising a plurality of second CBGs from the second UE; determine decoding error in one or more CB Gs among the first and second CBGs; generate a CBG failure mask indicating the decoding error, the CBG failure mask configured to indicate one or more time-frequency domain regions covering the one or more CBGs with the decoding error; and transmit the CBG failure mask to the first UE and the second UE to facilitate retransmission of the CBGs indicated by the CBG failure mask.
 17. The scheduling entity of claim 16, wherein one or more CBGs from the first UE are different in sizes from one or more CBGs from the second UE.
 18. The scheduling entity of claim 16, wherein the processor and the memory are further configured to: receive the first UL transmission in a first subband; and receive the second UL transmission in a second subband that is different from the first subband.
 19. The scheduling entity of claim 16, wherein the processor and the memory are further configured to: transmit a first retransmission grant to the first UE; and transmit a second retransmission grant, separated from the first retransmission grant, to the second UE, wherein the CBG failure mask is transmitted in a first slot, and wherein the first retransmission grant or the second retransmission grant is transmitted in the first slot or a later slot.
 20. The scheduling entity of claim 19, wherein the first retransmission grant and the second retransmission grant are configured to indicate at least one of the existence or location of the corresponding CBG failure mask.
 21. The scheduling entity of claim 16, wherein the processor and the memory are further configured to: transmit the CBG failure mask in a common search space of the first UE and the second UE.
 22. The scheduling entity of claim 16, wherein the CBG failure mask comprises a first CBG failure mask used by the first UE and a second CBG failure mask used by the second UE.
 23. The scheduling entity of claim 22, wherein the processor and the memory are further configured to: transmit a first retransmission grant to the first UE, wherein the first retransmission grant signals the first UE to utilize the first CBG failure mask, wherein the first CBG failure mask is associated with a first subband for transmitting the first UL transmission; and transmit a second retransmission grant to the second UE, wherein the second retransmission grant signals the second UE to utilize the second CBG failure mask, wherein the second CBG failure mask is associated with a second subband for transmitting the second UL transmission.
 24. The scheduling entity of claim 16, wherein the processor and the memory are further configured to: transmit a first CBG failure mask in a first control message to a first set of UEs including the first UE; and transmit a second CBG failure mask in a second control message to a second set of UEs including the second UE.
 25. The scheduling entity of claim 24, wherein the processor and the memory are further configured to: transmit a first retransmission grant to signal the first UE to utilize the first CBG failure mask; and transmit a second retransmission grant to signal the second UE to utilize the second CBG failure mask.
 26. A first user equipment (UE), comprising: a communication interface configured to communicate with a scheduling entity; a memory; and a processor operatively coupled to the communication interface and the memory, wherein the processor and the memory are configured to: transmit an uplink (UL) transmission to the scheduling entity, the UL transmission carrying a plurality of code block groups (CBGs); receive a CBG failure mask from the scheduling entity, the CBG failure mask comprising a time-frequency domain region designated for CBG retransmission; compare time-frequency resources of the transmitted CBGs with time-frequency resources in the time-frequency domain region of the CBG failure mask, to determine one or more of the CBGs for retransmission; and transmit the one or more CBGs for retransmission.
 27. The first UE of claim 26, wherein the processor and the memory are further configured to: transmit the UL transmission in a first subband that is different from a second subband allocated to a second UE that receives the same CBG failure mask.
 28. The first UE of claim 26, wherein the processor and the memory are further configured to: receive a first retransmission grant, separated from a second retransmission grant for a second UE, from the scheduling entity, wherein the CBG failure mask comprises a first CBG failure mask for the first UE and a second CBG failure mask for the second UE, wherein the first retransmission grant signals the first UE to utilize the first CBG failure mask for CBG retransmission using a CBG based retransmission process, and wherein the second retransmission grant signals the second UE to utilize the second CBG failure mask for CBG retransmission using a CBG based retransmission process.
 29. The first UE of claim 28, wherein the CBG failure mask is received in a first slot, and wherein the first retransmission grant is received in the first slot or a second slot later than the first slot.
 30. The first UE of claim 26, wherein the processor and the memory are further configured to: receive the CBG failure mask in a common search space of the first UE and a second UE that receives the same CBG failure mask. 